The present invention is directed to a large bore retrievable well safety valve such as described in U.S. Pat. No. 4,854,387 and U.S. patent application Ser. No. 07/404,241, filed Sept. 7, 1989, now U.S. Pat. No. 4,926,945. Such valves are designed to provide large bores thus increasing well production through the valves. However, such valves have a separate nose subassembly. Because of the nose assembly, separate trips into the well and out of the well for setting and removing such a safety valve are required. In addition, the nose assembly includes a mating downstop which may include a nose seal and must be oriented relative to the valve in a landing nipple.
The present invention is directed to a safety valve which utilizes a one-piece mount which contains and supports both the arcuate wrap-around flapper as well as the downstop for mating against the valve flow tube. The single piece mount of the present invention has the advantage in that it (1) allows easy assembly of parts which need to be oriented, (2) allows better reliability of mating the flow tube in the nose by insuring that the orientation of the nose and the flow tube are matched, (3) allows more precise calibration of the safety valve and power spring by closely held dimensions and (4) allows easier setting and retrieving of the wireline assembly using fewer trips and fewer different types of equipment.